Fair brother Lecture now on YouTube!

Here’s the final film of the public lecture I gave in May. Have a look, I absolutely promise it should be accessible to everyone, that’s the idea! Some of my friends were worried about coming incase they wouldn’t understand it and reviews have been pretty nice so I hope you will enjoy it too…

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Is the climate changing or are we just lost in translation?

We can spend a lot of time worrying about unlikely probabilities. (Image news.com.au)

We can spend a lot of time worrying about unlikely probabilities. (Image news.com.au)

Fear of flying- it’s something that many of us have, and even those who don’t can at least understand what there is to be afraid of. Planes crash, there’s no two ways about it. Yet to have a fear of climate change? That seems a lot less logical. Why is it we focus on the remote probability but often don’t spare a thought for something that is a lot more likely to have an impact on us?

Maybe for the case of climate change it’s due to not knowing the numbers involved- is this “dangerous” level of climate change politicians like to focus on something that will actually happen? If we somehow manage to keep carbon dioxide concentrations at the current level of about 400 parts per million, (bearing in mind that this level was exceeded in May 2013 at Mauna Loa in Hawaii for the first time since 1958 and in April 2014 became a monthly average) then the chances of 2 degrees warming in relation to pre-industrial levels is 30%. 2 degrees is a figure that should be prevented according to the UN and the EU and is often quoted as being a dangerous level, bringing with it global consequences including significant increase in wildfire, sea level rise and decreasing crop yields. But 30% likelihood doesn’t sound so bad, or does it?

Put this into a context we might better understand and this figure doesn’t look so good. There are currently an average of 30 fatal flying accidents per year. If the probability of fatal flying accidents was the same as the chance of 2 degrees warming this figure would rise to over 9 million. That’s over one thousand fatal flying accidents per hour. Increase carbon dioxide concentration to 450 parts per million and this figure nearly doubles.

But then again even if we knew the statistics, would that matter? Maybe it’s an inherent fear of numbers that GCSE or O level maths leaves countless people with but in the UK we as a nation tend not to be comfortable with probabilities. European weather forecasts frequently give a percentage likelihood of rain but here the closest we really get is being told there is a slight chance of showers.

This does lead to another problem though, what does “slight chance” actually mean? Do I pack my umbrella? In the case of climate change it may well be the wording that is the problem not the numbers. The Intergovernmental Panel on Climate Change (the ‘IPCC’) use a scale of phrases to describe the probabilities of events ranging from ‘virtually certain ‘ to ‘considerably unlikely’.

A study by the University College London, Cardiff University and Shandong Normal University in China showed just how big the problem with these terms is. Only 20% of UK participants could correctly put the IPCC’s terms into the order of increasing likelihood that they were intended to represent, let alone determine what ranges of probabilities that they are trying to demonstrate. Chinese participants scored even lower than this with only 9% completing a correct order. The understanding of the terms used for the Chinese version of the IPCC report for most native Chinese speakers did not agree with the IPCC’s definition, especially for the higher probability terms such as ‘very likely’ which the IPCC believe should represent over 90% probability but was being interpreted by Chinese participants as only 70% likely. So we have an intergovernmental report, designed to give a clear guide to the world on the best that science has to tell us about the state of the climate but a wide range of ways people interpret the terms they’re using.

Maybe using numbers is the way forward, or maybe scientists are just not using the right words. Many of those with a science background have constantly been told throughout school, undergraduate degrees and beyond that climate change is happening. Perhaps for scientists the language is less important and we just don’t think how a choice of words can affect those who are less convinced.

There is much debate around whether or not scientists should get involved in policy or try to get certain messages out to the public. Some feel that science should be done just for science’s sake whether or not everyone else can understand it. But with funding bodies demanding outreach work and big publications, coupled with a great deal of taxpayers’ money funding research, the science has to be shared, regardless of how people choose to interpret it. For this to happen it needs to be clear what scientists are actually trying to show when they use probabilities and it seems that in the case of climate change this is still not happening. Will this change in the future? I’d say it’s very slightly somewhat considerably likely.

References:

  1. Statistics created using http://global-risk-indicator.net/index.html It’s a really cool tool, go and play with it.
  2. Study mentioned: Lost in translation? Interpretations of the probability phrases used by the Intergovernmental Panel on Climate Change in China and the UK- Harris et al, Climatic Change (2013), 121:415–425, DOI 10.1007/s10584-013-0975-1

Penguins are going climbing to adapt to climate change!

An emperor penguin (image Photo Volcania)

Until recently it was thought that all emperor penguins bread on fast ice, that’s sea ice attached to the land; much easier to navigate than the cliffs of ice shelves (image Photo Volcania).

It has been well publicised recently that despite sea ice in the Arctic decreasing, sea ice in the Antarctic has been on the increase. Emperor penguins breed on sea ice, so surely this would be a good thing for the penguins?

Unfortunately, this isn’t the case- even though there is more ice forming it’s forming too late for the penguins’ breeding season. The climate of Antarctica is changing, it has warmed more than 5 times the global average over the last century. It is thought that one of the colonies discovered moved as a result of the late arrival of the sea ice, potentially due to a changing climate.

Penguin colonies can actually be spotted in satellite images such as the one below and it was a combination of this and aerial views from planes that alerted scientist to the fact that these colonies that have moved onto ice shelves.

A satellite image of an emperor penguin colony on an ice shelf (Image BAS/Digital Global).

A satellite image of an emperor penguin colony on an ice shelf (Image BAS/Digital Global). Guano is a term for penguin excrement.

It’s not known quite how the penguins manage to climb up cliffs onto the ice shelves as the colonies haven’t been studied up close but it is thought they might be able to shuffle up between ridges formed by draining water on the ice shelves.

Although it is bad news that the penguins are having to do this it’s a nice positive in their chances of future survival. Polar regions warm faster than other areas so this may not be the end of unusual penguin behaviour if the planet continues to warm.

An emperor penguin huddle. The males are left to look after the eggs while the females go off and hunt, they hiddle together to try and survive the freezing conditions such as during the blizzard shown here (image Australian Antarctic Division).

An emperor penguin huddle. The males are left to look after the eggs while the females go off and hunt, they huddle together to try and survive the freezing conditions such as during the blizzard shown here (image Australian Antarctic Division).

 

References:

The original research article (Fretwell et al.) is http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0085285

Antarctica in the news: Ice is being lost now and at twice the rate previously thought

What’s happened?

Radar measurements have shown that Antarctica is losing ice at twice the rate previously estimated- it is contributing to 0.45mm of sea level rise per year.

This work was carried out by the Centre for Polar Observation and Modelling (CPOM) at Leeds University- CPOM are the group I’m part of but I’m in the Reading branch so this is extra exciting.

 

Ice loss from Antarctica- look towards the West, the area that was in the news last week. Image ESA/CPOM/M.McMillan/Leeds Uni

Ice loss from Antarctica- look towards the West, the area around the Amundsen Sea was in the news last week. Image ESA/CPOM/M.McMillan/Leeds Uni

How much is being lost?

0.45mm of sea level rise  might not sound like a lot but in terms of the amount of ice involved that’s 159 billion tonnes of ice disappearing each year- to use a media favorite comparison I make that over 6 million Olympic sized swimming pools of ice.

Isn’t  Antarctica supposed to be gaining ice?

Sea ice around Antarctica has been increasing recently (this could be for several reasons including changes in ocean circulation and weather) but this is only sea ice- frozen sea water, floating on the sea. The ice loss in this study is ice coming from off of the land and going into the ocean.

 Extra bit of cool science

The reason this radar information is so much better than anything we’ve had previously is because the satellite involved, Cryosat can penetrate cloud. Previous satellites couldn’t do this so estimates had to be made wherever there was cloud suing information from cloud free areas. We now have 96% satellite coverage of Antarctica which makes monitoring future changes much easier.

Antarctica in the news: The ‘unstoppable’ collapse of the West Antarctic Ice Sheet

Thwaites glacier (Image from NASA ICE)

Thwaites glacier (Image from NASA ICE)

What’s happening?

Two studies hit headlines (confusingly several media articles reported either one or both of them with similar headlines) this week that suggest that glaciers on the West Antarctic Ice Sheet (WAIS), which was already thought to be vulnerable, are shrinking and are set to contribute significantly to sea level rise.

Map of Antarctica showing the Amundsen Sea, which glaciers of the WAIS flow into.

Map of Antarctica showing the Amundsen Sea, which glaciers of the WAIS flow into.

The outcome isn’t certain: we don’t know enough about Antarctica, it’s history and the Earth’s climate system to really say very much to 100% certainity- but here we have one study that is based on modelling a key glacier on the ice sheet (Thwaites Glacier) and one that is based on observations so the combination of the two provides strong evidence.

The first study models changes in Thwaites Glacier for different levels of melting and for all but the lowest level of melt the onset of rapid collapse of the glacier happens within a millenium (current observations match the higher end of the melting levels they melted, this would have collapse somewhere within the next 300 years or so). The second study  is based on observations that several glaciers are melting faster than most scientist had expected.

Thwaites Glacier meeting the ocean (Image NASA ICE).

Thwaites Glacier meeting the ocean (Image NASA ICE).

 

How much ice are we talking here?

The loss of the whole West Antarctic ice sheet would contirbute 3.3m of sea level rise, and just the glaciers in the 2nd study could contribute over 1.2m between them. However, as mentioned above this is over potentially long time scales but that still doesn’t mean that significant changes could happen, potentially within our lifetimes- these glaciers are already releasing the same amount of ice annually as Greenland.

So why is the WAIS so much at risk?

A simplified diagram of a grounding line (www.AntarcticGlaciers.org).

A simplified diagram of a grounding line (www.AntarcticGlaciers.org).

As the ice shelves coming from the glaciers are melting, they become lighter, meaning that they can float above areas where they used to be grounded. The point where the ice flows off of the land and becomes a floating ice shelf is called the grounding line and the grounding lines of the glaciers studies are moving further back towards the sources of the glaciers.

This retreat can be held back by “pinning points”, hills or bumps beneath the ice- a lack of these and the gerneal shape of the land below the ice reduced that WAIS’s ability to slow the glaciers down.

Bonus extra bit of cool science

You can watch a video by Eric Rignot, author of one of the 2nd study, with lots of exciting graphics and images of what’s underneath the WAIS here:

 

If this sounds interesting and you’d like a more in depth explanation I’d recommend heading here.

 

References:

1st study (Joughin et al.): http://www.sciencemag.org/content/344/6185/735

2nd Study (Rignot et al.): http://onlinelibrary.wiley.com/doi/10.1002/2014GL060140/abstract

Potential sea level rise from the west Antarctic ice sheet: http://www.sciencemag.org/content/324/5929/901

 

 

Can you find London?

This is well worth a play- what would the world look like if all of the ice melted? Toggle cities on for it to really hit home.

It is unclear from this if they’ve included the thermal expansion that would take place in the oceans if the earth was warm enough for all the ice to melt- sea levels also rise as the ocean warms so if this isn’t included the sea level rise in some areas would be significantly larger than this.

http://ngm.nationalgeographic.com/2013/09/rising-seas/if-ice-melted-map

If the Larsen C ice shelf (the one I look at) collapsed it wouldn’t contribute to sea level rise directly, but the glaciers feeding it are likely to speed up and this will, and by how much is unclear.